When I as a young man was on the losing side in the 1975 referendum on EEC membership, I did not think we should have a second referendum soon afterwards to try again to get us out. Indeed, more than 25 years past before I and others called for referenda on the Euro and the growing political union that the EEC had become. A referendum is designed to answer a question and make a decision for a decent period of time when it is about these fundamental constitutional matters.
The SNP will have time to consider what went wrong with their last case for so called independence, and what has gone wrong for them since that event. At current oil prices, with the rapid run down in oil output, their economic arithmetic needs reworking over what a Scottish budget would look like.
The rest of the UK would clearly insist on an independent Scotland leaving the pound. Being in a currency union requires each part of the Union to underwrite all parts of the Union socially, economically, and the banking system. English, Welsh and Northern Irish taxpayers would no longer be willing to do this for an independent Scotland.
Scotland would be out of the EU whether the UK is still in or out itself. The EU does not wish to encourage separatist movements within EU countries by offering them easy membership. Spain is insistent on this point given its refusal even to allow a referendum in Catalonia. Nor would Scotland as an applicant country be likely to be offered opt outs from the Euro and Schengen, nor a contribution rebate as the UK currently enjoys.
I was interested to read that the SNP now think maybe seeking to join EFTA would be better, so their argument that this is mainly about EU membership has not lasted a couple of days debate about a second referendum.